An introduction to practical chemistry : including analysis . ydrogen gas is givenoff (12). If in addition to the zinc and dilute sulphuricacid, either of the oxides of arsenic are present, the zincabstracts oxygen from them as well as from the water;and the metallic arsenic thus formed, combines, at themoment of its liberation, with some of the hydrogensimultaneously produced, and forms a gaseous com-pound called arseniuretted hydrogen (AsH3)5 which passesoff mixed with the excess of ^50:l-ffiZn+G(//0,?0:!)=G(ZrtO,>S03)+AsIT3+37/0. Now if this arseniuretted hydrogen is heated st
An introduction to practical chemistry : including analysis . ydrogen gas is givenoff (12). If in addition to the zinc and dilute sulphuricacid, either of the oxides of arsenic are present, the zincabstracts oxygen from them as well as from the water;and the metallic arsenic thus formed, combines, at themoment of its liberation, with some of the hydrogensimultaneously produced, and forms a gaseous com-pound called arseniuretted hydrogen (AsH3)5 which passesoff mixed with the excess of ^50:l-ffiZn+G(//0,?0:!)=G(ZrtO,>S03)+AsIT3+37/0. Now if this arseniuretted hydrogen is heated stronglyeither by burning in the air, or by passing through ared-hot tube, it is decomposed, and metallic arsenic orits oxide is deposited in the solid state, while the libe-rated hydrogen passes off. 1 It must be borne in mind that this gas, like most of the other com-pounds of arsenic, is highly poisonous ; so that the experiment shouldnever be performed in a close room, but in the open air or in a well-ventilated apartment. 118 METALS BELONGING TO CLASS IV. Marshs Test. 313. Several forms of apparatus have been contrivedfor making use of this property in the detection ofarsenic ;—of these the following is in practice the mostconvenient: The bottle a (Eig. 71) should be capable of containing six or eightounces of water, and isconnected by means of aperforated cork with thetubes b and c, which shouldbe about half an inch indiameter: to the latter isattached by means of acork, the tube d, whichshould be made of hardGerman glass, bent at aright angle, having the. end e drawn oft so as to dimmish the aperture. A few fragments of zinc areplaced in the bottle, and when the cork with its tubesis attached, pour a little dilute sulphuric acid down thetube b, which should reach nearly to the bottom of thebottle, and allow the gas (hydrogen) to be given off forfive Then heat the narrow tube with a spiritlamp at the point d, and observe carefully whetherthere is any deposit pro
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Keywords: ., bookcentury1800, bookdecade1850, booksubjectchemistry, bookyear18
